Probably every operator who has ever used a TIG torch has wanted a true fingertip controller for the welding current. The prior art offers numerous examples of torch-mounted controllers that purport to offer such control. Examples of torch-mounted controllers in the prior art are U.S. Pat. No. 6,051,808 to Kleppen, U.S. Pat. No. 4,227,066 to Bulwidas, and U.S. Pub. No. 2005/0023263 A1 to Bilde.
The prior art torch-mounted welding controllers have proved unsatisfactory so that most TIG operators still prefer to use a foot pedal control whenever possible Controllers taught in the prior art have the following problems:                They require the operator to alter his normal, preferred grip on the torch in order to reach the control with one or more fingers. In some cases, as with trigger type schemes, the grip required will be completely foreign to most operators.        Once the operator's finger has found the control knob or trigger, activation requires a large range of motion, involving many muscles of the hand; in fact, with many controllers you can't go from off to full power in one smooth motion, but must finger the controller repeatedly.        Many of these controllers require a fair amount of finger pressure, because they work by friction between the finger and a knob or belt.        Operation of the controller interferes with the operator's main task, which is maintaining an exact and very close height of the torch and electrode above the weld puddle.        
Accordingly, there remains a need for a troch-mounted welding controller that overcomes one or more of these problems.